A substrate treatment apparatus is an apparatus used in manufacturing processes of semiconductor devices, liquid crystal display panels, and the like, and configured to perform a treatment on a surface of a substrate such as a wafer and a liquid crystal substrate by supplying a treatment liquid (such as a resist stripping liquid and a cleaning liquid) to the surface of the substrate. As one of such substrate treatment apparatuses, there has been developed an apparatus configured to perform spin-processing by supplying a treatment liquid to approximately the center of a top surface of a substrate from a nozzle while horizontally rotating the substrate, and thereby spreading the treatment liquid over the surface of the substrate by centrifugal force. Moreover, there has also been developed an apparatus configured to jet a treatment liquid to a bottom surface of a rotating substrate in addition to its top surface from the nozzle, and thereby to perform a treatment on the two surfaces of the substrate.
When the substrate is increased in size, coverage of the treatment liquid over the substrate is reduced. In this case, however, a simple increase in amount of the treatment liquid leads to an increase in manufacturing cost. On the other hand, in order to improve the coverage of the treatment liquid over the substrate, the nozzle may be moved along the bottom surface of the substrate. In this case, however, the apparatus needs to be provided with a movement mechanism for the nozzle, which results in complication of the apparatus and accordingly an increase in equipment cost. Furthermore, if the movement mechanism moves the nozzle during the treatment, generation of dust or the like may occur and thereby lead to reduction in yield. From the viewpoints mentioned above, there is a demand for a technique that improves coverage of a treatment liquid over a substrate while suppressing an increase in manufacturing cost or equipment cost as well as reduction in yield.